package String;

import com.sun.xml.internal.ws.message.MimeAttachmentSet;

public class Test {
    public static void main(String[] args) {
        String s1 = "http://www.tedu.cn";
        String s2 = "www.tarena.com.cn";
        String n1 = getHostName(s1);
        String n2 = getHostName(s2);
        System.out.println(n1);//tedu
        System.out.println(n2);//tarena

    }
    public static String getHostName(String url){
//                         4
//                         v
//        String s2 = "www.tarena.com.cn";
        int start = url.indexOf(".")+1;//4
        int end = url.indexOf(".",start);
        String sub = url.substring(start,end);

        return sub;
    }

}
